What is the smallest part of an element that still retains properties of that element? a. molecule b. mixture c. compound d. atom

Plzz hurry im being timed during times of vigorous physical activity, muscles require a constant supply of oxygen. how does the body respond to these needs? a. breathing rate and heart rate both decrease. b. breathing rate and heart rate both increase. c. heart rate decreases, but breathing rate remains stable. d. breathing rate increases, but heart rate remains stable.

Tlymphocytes mature in the? a. thyroid gland. b. bone marrow. c. spleen. d. thymus.

An organism has the following traits multicellular cant photosynthesize has a skull. wht kingdom does this organism most likely belong too?